Convert Dictionary to Base64: error Segmentation fault 11 - swift

Question

I am trying to create JSON Web Token using JSONSerialization class, Swift 3 and Xcode 8.1, but my project fails to build with error:
Command failed due to signal: Segmentation fault 11.
Anyone knows why my code is not correct?
If I comment out this code from the project, the project builds.
let customerError = "Custom Error"
enum headerError: Error {
case customerError
}
let headerJWT: [Dictionary] = ["alg":"RS256","typ":"JWT"]
//Convert headerJWT to Data
do {
let headerJWTData: Data = try? JSONSerialization.data(withJSONObject:headerJWT,options: JSONSerialization.WritingOptions.prettyPrinted)
} catch headerError.customerError {
print("could not make data")
}
//Convert headerData to string utf8
do {
let headerJWTString = try String(data: headerJWTData,encoding:String.Encoding.utf8) as! String
} catch {
print("string could not be created")
}
//Convert headerJWTString to base64EncodedString
do {
let headerJWTBase64 = try Data(headerJWTString.utf8).base64EncodedString()
} catch {
"base64 could not be created"
}

Answer 1

Once you create the Data from using JSONSerialization, you simply use the method from Data to get a base64 encoded string.
let headerJWT: [Dictionary] = ["alg":"RS256","typ":"JWT"]
do {
let headerJWTData: Data = try? JSONSerialization.data(withJSONObject:headerJWT,options: JSONSerialization.WritingOptions.prettyPrinted)
let headerJWTBase64 = headerJWTData.base64EncodedString()
} catch headerError.customerError {
print("could not make data")
}
You can pass different options to base64EncodedString() depending on what format you need the base64 string to be in.